The proposal has significance in that it would establish the scientific capability, the administrative expertise and essential physical equipment for: 1. On-going pharmacologic study of established, effective oncologic drugs used in treating malignancies of childhood permitting: a. Rational rather than empirical dosage schedules, b. better understanding of toxicity and its prevention, c. comparison of pharmacokinetics in children with published data for adults with a view to determining age related differences, and d. monitoring for compliance to permit better evaluation of individuals, as well as groups of patients, to give the physician an opportunity to secure better compliance should it be lacking. 2. Pharmacologic evaluation of new formulations of drugs used in treating cancer in children. The actual research projected centers around the expertise of Dr. Nelson in applying methodology of cancer drugs to research and cancer problems.